The δ18O data for the last 8000 years in the Greenland NGRIP1, GRIP, DYE-3 and GISP2 ice cores have been analyzed stratigraphically in search of potentially meaningful boundaries and units. Pattern matching of the profiles is supported by using graphical display enhancements, calculating spectral trend curves and generating a compound profile. Techniques routinely used in subsurface geology have been applied in correlating the profiles. Four major stratigraphic units are identified (8.1–4.9, 4.9–3.3, 3.3–1.9 and 1.9–0.1 ka b2k), resulting in an improved understanding of the climate change after the Holocene Climate Optimum. Correlatable higher-order boundaries are identified within these units. The layers between the boundaries show δ18O patterns which generally are similar in character, the differences being ascribed to lateral variations in the factors that control the isotope content of the ice. The layering forms a series of short-lived low-amplitude aperiodic oscillations on a centennial time scale. The suggestion is that these higher-order boundaries and δ18O oscillations have climatic significance. Equivalent units are tentatively identified in ice-core data from the Agassiz and Renland ice caps. Comparison with other climate proxies or stratigraphies from the Northern Hemisphere is expected to render support for the here proposed scheme. It will then serve to guide and constrain the analysis of the dynamics of the climatic fluctuations for the study period.
The objective of this research is to determine the impact of waves on the segregation of sediment within the area of its supply in the context of meteorological conditions. The research was conducted on a 4 km section of the shore of Calypsostranda (Bellsund, West Spitsbergen), shaped by waves such as swell, wind waves, and tides. Particular attention was paid to the diversity and variability of the surface texture within the intertidal zone. Meteorological measurements, recording of wave climate, as well as analysis of the grain-size distribution of the beach sediments were performed. Nearshore bathymetry, longshore drifts, episodic sediment delivery from land, as well as resistance of the shore to coastal erosion and direction of transport of sediments in the shore zone are important factors controlling shore development. Data show that wind waves contribute to erosion and discharge of material from the nearshore and intertidal zone. The research also shows that oceanic swell, altered by diffraction, reaching the shore of Calypsostranda contributes to better sorting of sediment deposited on the shore through washing it out from among gravels, and longshore transport of its finest fraction. The grain size distribution of shore sediments is significantly changed already during one tidal cycle. The degree of this modification depends not only on wave height and period but on the direction of wave impact. The shore of Calypsostranda can be regarded as transitional between high and low energy coasts.
Humic acids, isolated from selected soils of Grønfjorden area (Spitsbergen) were investigated in terms of molecular composition and resistance of decomposition. The degree of soils organic matter stabilization has been assessed with the use of modern instrumental methods (nuclear magnetic resonance spectroscopy (CP/MAS 13C-NMR). Analysis of the humic acids showed that aromatic compounds prevail in the organic matter formed in cryoconites, located on the glaciers surfaces. The predominance of aliphatic fragments is revealed in the soils in tidal zone that form on the coastal terrace. This could be caused by sedimentation of fresh organic matter exhibiting low decomposition stage due to the harsh climate and processes of hydrogenation in the humic acids, destruction of the C-C bonds and formation of chains with a high hydrogen content. These processes result in formation of aliphatic fragments in the humic acids. In general, soils of the studied region characterizes by low stabilized soil organic matter which is indicated by low aromaticity of the HAs.
This is a short report about the first Cenozoic shark fossil from Svalbard. The specimen derives from the late Paleocene greenish sandstone of the Grumantbyen Formation, which is exposed in Fossildalen on the western side of Colesbukta on Spitsbergen. The single tooth is assigned to the Paleogene sand tiger shark genus Striatolamia that also is known from other polar regions. The Fossildalen specimen represents the northernmost Paleogene shark record, and is the second reported body fossil of a vertebrate from the Cenozoic of Spitsbergen.
Here are reported the first certainly indigenous agglutinated foraminifera known for the Eocene La Meseta Formation on Seymour Island, West Antarctica. The specimens were identified as Textularia sp. and occur in the upper portion of the unit, just below the contact with the overlying post-Eocene deposits. Despite being rare, the specimens are interpreted as autochthonous or parautochthonous due to their overall good preservation, fragility, and lack of sedimentary filling. The La Meseta Formation seems to have passed through a major diagenetic dissolution of calcareous microfossils, but the present findings suggest that indigenous agglutinated foraminifera can be found at least in some of its strata.
Information on lichens of Franz Josef Land is summarized based on original and literature data. Two hundred twenty nine lichen species are documented, of which 59 species and two varieties are newly reported for this territory. This represents only 13% of the Arctic lichen flora richness. We have found 28 rare lichen species in the archipelago and recommend to include 9 species in the Red Data Book of the Arkhangelsk Region of Russia.
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